Pyrazolo-triazoles and use of said compounds for dyeing keratinous fibres

ABSTRACT

The subject of the invention is novel pyrazolo[3,2-c]-1,2,4-triazoles of formula (I) which are useful for the oxidation dyeing of keratinous fibers, in particular human hair, the compositions containing these compounds and the dyeing method using them. 
                         
in which
         R1 represents a hydroxyl group or a C1–C4 alkyl group substituted with at least one hydroxyl radical, and R2 represents an aryl group which may be substituted with at least one radical chosen from the group consisting of halogen, nitro, cyano, alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino, sulfonamido, alkylthio, alkoxycarbonyl, carboxy and sulfo radicals.

The subject of the invention is novel pyrazolo[3,2-c]-1,2,4-triazoleswhich are useful for the oxidation dyeing of keratinous fibers, inparticular human hair, the compositions containing these compounds andthe dyeing method using them.

It is known to dye keratinous fibers, and in particular human hair, withdyeing compositions containing oxidation dye precursors, generallycalled oxidation bases, such as ortho- or para-phenylenediamines, ortho-or para-aminophenols and heterocyclic compounds. These oxidation basesare colorles's or weakly colored compounds which, combined withoxidizing products, can give rise, through a process of oxidativecondensation, to colored compounds.

It is also known that it is possible to vary the shades obtained withthese oxidation bases by combining them with couplers or color modifiersthe latter being chosen in particular from aromatic meta-diamines,meta-aminophenols, meta-diphenols and certain heterocyclic compoundssuch as indole compounds.

The variety of molecules used in oxidation bases and couplers allows arich palette of colors to be obtained.

The so-called “permanent” color obtained using these oxidation dyes mustmoreover satisfy a number of requirements. Thus, it must be withoutdrawbacks from the toxicological point of view, it must make it possibleto obtain shades in the desired intensity and exhibit good resistancetoward external agents such as light, adverse weather conditions,washing, permanent waving, perspiration and rubbing.

The dyes must also make it possible to cover gray hair and must finallybe the least selective possible, that is to say make it possible toobtain the smallest possible differences in color right along the samekeratinous fiber, which is generally differently sensitized (i.e.damaged) between its tip and its root.

It is already known to use pyrazoloazole compounds as couplers fordyeing keratinous fibers. For example, patent application FR 2 746 306describes compositions for dyeing keratinous fibers containing suchcouplers. These compositions are nevertheless not completelysatisfactory, in particular they are not completely satisfactory fromthe point of view of the purity of the shades.

The aim of the present invention is to provide novel dyeing compositionsnot having the drawbacks of those of the prior art. In particular, theaim of the present invention is to provide compositions for theoxidation dyeing of keratinous fibers which have powerful dyes, whichare scarcely selective and are particularly resistant, which are capableof generating intense colorations in a variety of shades, and which havea coloration which scarcely varies during a deferred application.

This aim is achieved with the present invention whose subject is a novelpyrazolo[3,2-c]-1,2,4-triazole of formula (I) or one of its additionsalts with an acid or a base:

in which

-   -   R1 represents a hydroxyl group or a C1–C4 alkyl group        substituted with at least one hydroxyl radical, and R2        represents an aryl, for example phenyl or naphthyl, group which        may be substituted with at least one radical chosen from the        group consisting of halogen, nitro, cyano, alkyl, hydroxyl,        alkoxy, amino, alkylamino, dialkylamino, acylamino, sulfonamido,        alkylthio, alkoxycarbonyl, carboxy and sulfo radicals.

According to a particular embodiment, R1 is a C1–C4 alkyl group whichare substituted with 1 to 3 hydroxyl radicals and R2 is a phenyl groupwhich may be substituted with 1 to 3 radicals, preferably 1 to 2radicals.

R1 is for example chosen from hydroxymethyl, 2-hydroxyethyl,3-hydroxypropyl, 1-hydroxyethyl, 1-hydroxypropyl,1-methyl-2-hydroxyethyl, 1,2-dihydroxyethyl, 2,3-dihydroxypropyl,1,3-dihydroxypropyl, 1,3-dihydroxybutyl, 2,4-dihydroxybutyl,1,2,3-trihydroxypropyl, 1,2,3-trihydroxybutyl. Preferably, R1 is chosenfrom hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl,1-methyl-2-hydroxyethyl, 1,2-dihydroxyethyl.

R2 is for example chosen from a phenyl group or a phenyl groupsubstituted with radicals chosen from halogen, C1–C4 alkyl, C1–C4alkoxy, hydroxyl, carboxyl, C1–C4 alkylthio, amino, C1–C4 alkylamino,C1–C4 dialkylamino and methylenedioxy radicals. Preferably, R2 is chosenfrom phenyl, toluyl, 2-, 3- or 4-chlorophenyl, 3- or 4-hydroxyphenyl, 3-or 4-aminophenyl and 3- or 4-methoxyphenyl. According to a particularlypreferred embodiment, the groups R2 are chosen from phenyl, toluyl, 3-or 4-hydroxyphenyl and 3- or 4-aminophenyl.

In the above definitions, the alkyl radicals or groups are linear orbranched and comprise, unless otherwise stated, from 1 to 10 carbonatoms, preferably 1 to 6 carbon atoms.

Among the pyrazolo[3,2-c]-1,2,4-triazoles of formula (I), there may bementioned in particular the following compounds or their addition saltswith an acid or a base:

-   6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(p-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(o-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(m-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(3-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(4-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(3-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(4-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-phenylpyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(p-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(o-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(m-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(3-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(4-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(3-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(2-hydroxyethyl)-3-(4-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-phenylpyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(p-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(o-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(m-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(3-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(4-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(3-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-(1-hydroxyethyl)-3-(4-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole.

Preferably, the pyrazolo[3,2-c]-1,2,4-triazoles of formula (I) arechosen from the following compounds or their addition salts with an acidor a base:

-   6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(p-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(o-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(m-toluyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(3-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(4-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(3-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole-   6-hydroxymethyl-3-(4-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole.

The compounds of the present invention may be obtained from the methodsof preparation described for example in patent application FR 2 746 306,and in the following publications: Chem. Ber. 32, 797 (1899), Chem. Ber.89, 2550, (1956), J. Chem. Soc. Perkin trans I,2047, (1977), J. Prakt.Chem., 320, 533, (1978), J. fur Chem., 326(5), 829, (1984).

The subject of the invention is also a composition for dyeing keratinousfibers, and in particular human keratinous fibers such as hair,comprising, in an appropriate dyeing medium, at least onepyrazolotriazole coupler of formula (I) or one of these addition saltswith an acid or a base as defined above and at least one oxidation base.

The oxidation base is chosen from the oxidation bases conventionallyused in oxidation dyeing, for example para-phenylenediamines,bisphenylalkylenediamines, para-aminophenols, ortho-aminophenols andheterocyclic bases, and their addition salts with an acid.

Among the para-phenylenediamines, there may be mentioned by way ofexample para-phenylenediamine, para-tolylenediamine,2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine,N,N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylenediamine,4-amino-N,N-diethyl-3-methylaniline,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,4-N,N-bis(β-hydroxyethyl)amino-2-methylaniline,4-N,N-bis(β-hydroxyethyl)amino-2-chloroaniline,2-β-hydroxyethyl-para-phenylenediamine, 2-fluoro-para-phenylenediamine,2-isopropyl-para-phenylenediamine,N-(β-hydroxypropyl)-para-phenylenediamine,2-hydroxymethyl-para-phenylenediamine,N,N-dimethyl-3-methyl-para-phenylenediamine,N,N-(ethyl-β-hydroxyethyl)-para-phenylenediamine,N-(β,γ-dihydroxypropyl)-para-phenylenediamine,N-(4′-aminophenyl)-para-phenylenediamine,N-phenyl-para-phenylenediamine,2-β-hydroxyethyloxy-para-phenylenediamine,2-β-acetylaminoethyloxy-para-phenylenediamine,N-(β-methoxyethyl)-para-phenylenediamine, and their addition salts withan acid.

Among the para-phenylenediamines mentioned above, there are particularlypreferred para-phenylenediamine, para-tolylenediamine,2-isopropyl-para-phenylenediamine,2-β-hydroxyethyl-para-phenylenediamine,2-β-hydroxyethyloxy-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,3-dimethyl-para-phenylenediamine,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,2-chloro-para-phenylenediamine,2-β-acetylaminoethyloxy-para-phenylenediamine, and their addition saltswith an acid.

Among the bisphenylalkylenediamines, there may be mentioned by way ofexampleN,N′-bis(β-phydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(4-aminophenyl)-tetramethylenediamine,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(4-methylaminophenyl)tetramethylenediamine,N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methylphenyl)ethylenediamine,1,8-bis(2,5-diaminophenoxy)-3,6-dioxaoctane, and their addition saltswith an acid.

Among the para-aminophenols, there may be mentioned by way of examplepara-aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluorophenol,4-amino-3-hydroxymethylphenol, 4-amino-2-methylphenol,4-amino-2-hydroxymethylphenol, 4-amino-2-methoxymethylphenol,4-amino-2-aminomethylphenol,4-amino-2-(β-hydroxyethylaminomethyl)phenol, 4-amino-2-fluorophenol, andtheir addition salts with an acid.

Among the ortho-aminophenols, there may be mentioned by way of example2-aminophenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol,5-acetamido-2-aminophenol, and their addition salts with an acid.

Among the heterocyclic bases, there may be mentioned by way of examplepyridine derivatives, pyrimidine derivatives and pyrazole derivatives.

Among the pyridine derivatives, there may be mentioned the compoundsdescribed for example in Patent GB 1,026,978 and GB 1,153,196, as wellas 2,5-diaminopyridine, 2-(4-methoxyphenyl)amino-3-aminopyridine,2,3-diamino-6-methoxypyridine, 2-(β-methoxyethyl)amino-3-amino-6-methoxypyridine, 3,4-diaminopyridine, and their acidaddition salts with an acid.

Among the pyrimidine derivatives, there may be mentioned the compoundsdescribed for example in Patents DE 2,359,399; JP 88-169,571; JP05,163,124; EP 0,770,375 or Patent Application WO 96/15765, such as2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine,2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine,2,5,6-triaminopyrimidine, and the pyrazolopyrimidine derivatives such asthose mentioned in Patent Application FR-A-2,750,048 and among whichthere may be mentioned pyrazolo[1,5-a]pyrimidine-3,7-diamine;2,5-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine;pyrazolo[1,5-a]pyrimidine-3,5-diamine;2,7-dimethylpyrazolo[1,5-a]pyrimidine-3,5-diamine;3-aminopyrazolo[1,5-a]pyrimidin-7-ol;3-aminopyrazolo[1,5-a]pyrimidin-5-ol;2-(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)ethanol,2-(7-aminopyrazolo[1,5-a]pyrimidin-3-ylamino)ethanol,2-[(3-aminopyrazolo[1,5-a]pyrimidin-7-yl)(2-hydroxyethyl)amino]ethanol,2-[(7-aminopyrazolo[1,5-a]pyrimidin-3-yl)-(2-hydroxyethyl)amino]ethanol,5,6-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,2,6-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,2,5,N7,N7-tetramethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,3-amino-5-methyl-7-imidazolylpropylaminopyrazolo[1,5-a]pyrimidine andtheir addition salts with an acid and their tautomeric forms, when atautomeric equilibrium exists.

Among the pyrazole derivatives, there may be mentioned the compoundsdescribed in Patents DE 3,843,892, DE 4,133,957 and Patent ApplicationsWO 94/08969, WO 94/08970, FR-A-2,733,749 and DE 195 43 988 such as4,5-diamino-1-methylpyrazole, 4,5-diamino-1-(β-hydroxyethyl)pyrazole,3,4-diaminopyrazole, 4,5-diamino-1-(4′-chlorobenzyl)pyrazole,4,5-diamino-1,3-dimethylpyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole,4,5-diamino-1-methyl-3-phenylpyrazole,4-amino-1,3-dimethyl-5-hydrazinopyrazole,1-benzyl-4,5-diamino-3-methylpyrazole,4,5-diamino-3-tert-butyl-1-methylpyrazole,4,5-diamino-1-tert-butyl-3-methylpyrazole,4,5-diamino-1-(β-hydroxyethyl)-3-methylpyrazole,4,5-diamino-1-ethyl-3-methylpyrazole,4,5-diamino-1-ethyl-3-(4′-methoxyphenyl)pyrazole,4,5-diamino-1-ethyl-3-hydroxymethylpyrazole,4,5-diamino-3-hydroxymethyl-1-methylpyrazole,4,5-diamino-3-hydroxymethyl-1-isopropylpyrazole,4,5-diamino-3-methyl-1-isopropylpyrazole,4-amino-5-(2′-aminoethyl)amino-1,3-dimethylpyrazole,3,4,5-triaminopyrazole, 1-methyl-3,4,5-triaminopyrazole,3,5-diamino-1-methyl-4-methylaminopyrazole,3,5-diamino-4-(β-hydroxyethyl)amino-1-methylpyrazole, and their additionsalts with an acid.

In the composition of the present invention, the pyrazolotriazolecoupler(s) are present in a quantity preferably of between 0.001 and 10%by weight approximately of the total weight of the dyeing compositionand still more preferably from 0.005 to 6%, and the oxidation base(s)are present in a quantity preferably of between 0.001 to 10% by weightapproximately of the total weight of the dyeing composition, and stillmore preferably from 0.005 to 6%.

The composition according to the invention may contain, in addition tothe pyrazolotriazole coupler of formula (I), one or more additionalcouplers which are conventionally used for dyeing keratinous fibers.Among these couplers, there may be mentioned in particularmeta-phenylenediamines, meta-aminophenols, meta-diphenols andheterocyclic couplers.

By way of example, there may be mentioned 2-methyl-5-aminophenol,5-N-(β-hydroxyethyl)amino-2-methylphenol,6-chloro-2-methyl-5-aminophenol, 3-aminophenol, 1,3-dihydroxybenzene,1,3-dihydroxy-2-methylbenzene, 4-chloro-1,3-dihydroxybenzene,2,4-diamino-1-(β-hydroxyethyloxy)benzene,2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis(2,4-diaminophenoxy)propane, 3-ureidoaniline,3-ureido-1-dimethylaminobenzene, sesamol,1-β-hydroxyethylamino-3,4-methylenedioxybenzene, α-napthol,2-methyl-1-naphthol, 6-hydroxyindole, 4-hydroxyindole,4-hydroxy-N-methylindole, 2-amino-3-hydroxypyridine,6-hydroxybenzomorpholine, 3,5-diamino-2,6-dimethoxypyridine,1-N-(β-hydroxyethyl)amino-3,4-methylenedioxybenzene,2,6-bis(β-hydroxyethylamino)toluene and their addition salts.

When they are present, the additional coupler(s) preferably representfrom 0.001 to 10% by weight approximately of the total weight of thedyeing composition and still more preferably from 0.005 to 6%.

In general, the addition salts with an acid which can be used in thecontext of the dyeing compositions of the invention for the oxidationbases and the couplers are chosen in particular from hydrochlorides,hydrobromides, sulfates, citrates, succinates, tartrates, lactates,tosylates, benzenesulfonates, phosphates and acetates. The additionsalts with a base which can be used in the context of the invention arefor example chosen the addition salts with sodium hydroxide, potassiumhydroxide, aqueous ammonia, amines or alkanolamines.

The dyeing composition in accordance with the invention may additionallycontain one or more direct dyes which may be chosen in particular fromnitro dyes of the benzene series, cationic direct dyes, azo direct dyesand methine direct dyes.

The appropriate dyeing medium, also called dye carrier, generallyconsists of water or of a mixture of water and at least one organicsolvent for solubilizing the compounds which might not be sufficientlysoluble in water. By way of organic solvent, there may be mentioned forexample C₁–C₄ lower alkanols such as ethanol and isopropanol; glycerol;glycols and glycol ethers such as 2-butoxyethanol, propylene glycol,propylene glycol monomethyl ether, diethylene glycol monoethyl ether andmonomethyl ether, and aromatic alcohols such as benzyl alcohol orphenoxyethanol, and mixtures thereof.

The solvents may be present in proportions preferably of between 1 and40% by weight approximately relative to the total weight of the dyeingcomposition, and still more preferably between 5 and 30% by weightapproximately.

The dyeing composition in accordance with the invention may alsocomprise various adjuvants which are conventionally used in hair dyeingcompositions, such as anionic, cationic, nonionic, amphoteric orzwitterionic surfactants or mixtures thereof, anionic, cationic,nonionic, amphoteric or zwitterionic polymers or mixtures thereof,inorganic or organic thickeners, associative or otherwise, antioxidants,penetrating agents, sequestering agents, perfumes, buffers, dispersingagents, conditioning agents such as for example modified or unmodified,volatile or nonvolatile silicones, film-forming agents, ceramides,preservatives, opacifying agents.

The above adjuvants are generally present in a quantity, for each ofthem, of between 0.01 and 20% by weight relative to the weight of thecomposition.

Of course, persons skilled in the art will be careful to choose this orthese optional additional compounds such that the advantageousproperties which are intrinsically attached to the oxidation dyeingcomposition in accordance with the invention are not, or notsubstantially, impaired by the addition(s) envisaged.

The pH of the dyeing composition in accordance with the invention isgenerally between 3 and 12 approximately, and preferably between 5 and11 approximately. It may be adjusted to the desired value by means ofacidifying or alkalinizing agents customarily used in dyeing keratinousfibers or alternatively with the aid of conventional buffer systems.

Among the acidifying agents, there may be mentioned, by way of example,inorganic or organic acids such as hydrochloric acid, orthophosphoricacid, sulfuric acid, carboxylic acids such as acetic acid, tartaricacid, citric acid, lactic acid, and sulfonic acids.

Among the alkalinizing agents, there may be mentioned, by way ofexample, aqueous ammonia, alkali metal carbonates, alkanolamines such asmono-, di- and triethanolamines and their derivatives, sodium orpotassium hydroxides and the compounds having the following formula(III):

in which W is a propylene residue which is optionally substituted with ahydroxyl group or a C₁–C₄ alkyl radical; R₆, R₇, R₈ and R₉, which areidentical or different, represent a hydrogen atom, a C₁–C₄ alkyl orC₁–C₄ hydroxyalkyl radical.

The dyeing composition according to the invention may be provided invarious forms, such as in the form of liquids, creams, gels, or in anyother form appropriate for dyeing keratinous fibers, and in particularhuman hair.

The subject of the invention is also a method for dyeing keratinousfibers, and in particular human keratinous fibers such as hair, usingthe dyeing composition as defined above.

According to this method, the composition according to the presentinvention as defined above is applied to the fibers, the color beingdeveloped with the aid of an oxidizing agent. The color may be developedat acidic, neutral or alkaline pH, and the oxidizing agent may be addedto the composition of the invention just at the time of use or it may beused from an oxidizing composition containing it, which is appliedsimultaneously with or sequentially to the composition of the invention.

According to a particular embodiment, the composition according to thepresent invention is mixed, preferably at the time of use, with acomposition containing, in an appropriate dyeing medium, at least oneoxidizing agent, this oxidizing agent being present in a sufficientquantity to develop a coloration. The mixture obtained is then appliedto the keratinous fibers. After a leave-in time of 3 to 50 minutesapproximately, preferably 5 to 30 minutes approximately, the keratinousfibers are rinsed, washed with shampoo, rinsed again and then dried.

The oxidizing agents conventionally used for the oxidation dyeing ofkeratinous fibers are for example hydrogen peroxide, urea peroxide,alkali metal bromates, persalts such as perborates and persulfates,peracids and oxidase enzymes among which there may be mentionedperoxidases, oxidoreductases containing two electrons such as uricasesand oxygenases containing 4 electrons such as laccases. Hydrogenperoxide is particularly preferred.

The oxidizing composition may also contain various adjuvantsconventionally used in hair-dyeing compositions and as defined above.

The pH of the oxidizing composition containing the oxidizing agent issuch that after mixing with the dyeing composition, the pH of theresulting composition applied to the keratinous fibers preferably variesbetween 3 and 12 approximately, and still more preferably between 5 and11. It may be adjusted to the desired value by means of acidifying oralkalinizing agents customarily used in dyeing keratinous fibers and asdefined above.

The composition which is finally applied to the keratinous fibers may beprovided in various forms, such as in the form of liquids, creams, gelsor in any other form appropriate for dyeing keratinous fibers, and inparticular human hair.

Another subject of the invention is a multicompartment device or dyeing“kit” in which a first compartment contains the dyeing compositiondefined above and a second compartment contains the oxidizingcomposition. This device may be equipped with a means which makes itpossible to deliver the desired mixture to the hair, such as the devicesdescribed in patent FR-2-586 913 in the name of the applicant.

The subject of the present invention is finally a method forsynthesizing a compound of formula (II) from a compound of formula (III)

in which formulae R3 and R4, which are identical or different, representan aryl, for example phenyl or naphthyl, group which may be substitutedwith at least one radical chosen from the group consisting of halogen,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino and alkylthioradicals, the method comprising a step of reducing the carboxylfunctional group to an alcohol functional group.

R3 and R4 are for example chosen from a phenyl group or a phenyl groupsubstituted with one or two groups chosen from halogen, C1–C2 alkyl,C1–C2 alkoxy, hydroxyl, C1–C2 alkylthio, amino, C1–C2 alkylamino, C1–C2dialkylamino and methylenedioxy radicals. Preferably, R3 and R4 arechosen from phenyl, toluyl, 2-, 3- or 4-chlorophenyl, 3- or4-hydroxyphenyl, 3- or 4-aminophenyl, 3- or 4-methoxyphenyl. Accordingto a particularly preferred embodiment, the groups R3 and R4 are chosenfrom phenyl, toluyl, 3- or 4-hydroxyphenyl, 3- or 4-aminophenyl.

The method of synthesis is carried out in one or more stages accordingto the nature of the substituent R3.

When the groups R3 and R4 are different, the method comprises one ormore additional stages aimed at converting R3 to R4. Furthermore, thecompound (III) may be converted to an ester before the reduction stage.Such a modification may be useful for increasing the solubility of thecompound (III) and facilitating the reduction.

Thus, when R3 and R4 are identical, the reduction of the carboxylic acidfunctional group at the 6-position to an alcohol functional group may becarried out in a direct manner in a single step with the customaryreducing agents such as metal hydrides, for example LiAlH₄, DIBAL,NaAlEt₂H₂, LiAlH(OMe)₃ or borane, these reagents being introduced atleast in a stoichiometric quantity. Solvents used are for example THF,ethers or DME. This route of synthesis is represented by scheme 1 below.

According to the nature of the substituent R3, the solubility of thecompound (III) may be low in aprotic dipolar solvents. It may beadvantageous in this case to convert, in a first stage, the carboxylicacid functional group of the compound (III) to a methyl or ethyl esterfunctional group in order to increase the solubility of the compound(III), and then, in a second stage, to reduce the ester functional groupwith conventional reducing agents in an aprotic dipolar solvent in orderto obtain the corresponding compound (II). This embodiment isrepresented in scheme 2 below. The preparation of the methyl,respectively ethyl, ester is carried out by the customary methods suchas for example by reaction of the carboxylic acid functional group inmethanol, respectively in ethanol, in an acid medium.

When R3 and R4 are different, the chemical modifications of thesubstituent R3 may be carried out either on the compound (II) or on thecompound (III) according to the nature of the modifications to be madeor according to their ease of implementation on either of the compounds.In this case, the preparation of the compound (II) from the compound(III) may be carried out by any of the schemes 3 to 6 below

According to scheme 3, the compound (III) is converted to compound Aunder the operating conditions necessary for converting R3 to R4. Thecompound A is then reduced under the operating conditions alreadydescribed for obtaining compound (II).

According to scheme 4, the carboxylic acid functional group of thecompound (III) is converted to a methyl or ethyl ester in order to formthe compound B according to the methods described above. The compound Bis then reduced under the operating conditions already described forobtaining compound (II).

A particular embodiment is described in scheme 5, according to which themethyl or ethyl ester of the compound (II) is prepared in a first stageby one of the methods already cited for synthesizing the compound Cwhich is more soluble than the compound (II) in aprotic dipolarsolvents. The compound C is then reduced for example by means of a metalhydride or borane as already indicated, in order to obtain the compoundD. It is then possible to carry out the desired chemical modification inorder to convert the substituent R3 to the substituent R4. If thesolubility of the compound (III) is sufficient, it is also possible todirectly reduce the carboxylic acid functional group at the 6-positionin order to prepare the compound D according to one of the methodsalready cited. The compound (II) is then prepared from the compound D.This variant is represented in scheme 6.

According to a particular embodiment, the synthesis of6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole of formula (II)may be carried out directly from6-carboxy-3-phenylpyrazolo[3,2-c]-1,2,4-triazole (III). It is preferablyobtained according to the procedure of scheme 2 which consists inconverting beforehand 6-carboxy-3-phenylpyrazolo[3,2-c]-1,2,4-triazoleto 6-carboxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole. The6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole may also beprepared from6-carboxy-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazoleaccording to one of schemes 3, 4, 5 or 6.

According to scheme 3,6-carboxy-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazole isconverted to 6-carboxy-3-phenylpyrazolo[3,2-c]-1,2,4-triazole forexample by catalytic reduction in the presence of a metal catalyst suchas palladium or palladium hydroxide at a hydrogen pressure of 2 to 100bar, preferably of 2 to 60 bar, at a temperature ranging from 10 to 90°C., preferably between 20 and 60° C. The reaction is preferably carriedout in a basic medium containing for example an organic base such as aprimary, secondary or tertiary amine, for example triethylamine,ethyldiisopropylamine or butylamine, or an inorganic base such as sodiumhydroxide, potassium hydroxide, potassium carbonate, sodium carbonate,potassium hydrogen carbonate, sodium hydrogen carbonate, or a mixture ofthese bases. The hydrogenation is carried out in a solvent such as analcohol, such as ethanol or methanol, in water, in an aqueous-alcoholicmixture or in a mixture of water and an aprotic dipolar solvent such asdioxane or THF. Preferably, the reaction is carried out in awater-aprotic dipolar solvent mixture. The6-carboxy-3-phenylpyrazolo[3,2-c]-1,2,4-triazole is then directlyreduced to 6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole(scheme 3) or is first of all esterified to a methyl or ethyl esterbefore being reduced (scheme 4).

According to scheme5,6-carboxy-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazole isfirst of all esterified to the compound C, the compound C is thenreduced in order to form6-hydroxymethyl-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazole.The conversion of the substituent R3=1-(3′,4′-dichloro)phenyl toR4=phenyl is carried out by catalytic hydrogenation under the conditionsalready described.

According to scheme 6, the carboxyl at the 6-position is first of allreduced to hydroxymethyl and then6-hydroxymethyl-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazoleis converted to 6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazoleby catalytic reduction under the above-mentioned conditions.

The subject of the invention is finally a colored product which can beobtained by reacting at least one pyrazolo[3,2-c]-1,2,4-triazole couplerof formula (I) or one of its addition salts with an acid or a base asdefined above, and at least one oxidation base.

The examples which follow serve to illustrate the invention withouthowever presenting a limiting character.

EXAMPLES Example 1 Synthesis of6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole (H) According toScheme 3

60 g of 6-carboxy-3-(3′,4′-dichloro)phenylpyrazolo[3,2-c]-1,2,4-triazoleE and 28.05 g of potassium carbonate are dissolved in 1.8 liters of amixture composed of 69 ml of 6 N sodium hydroxide and dioxane at 50% inwater. This solution is transferred into a hydrogenator and supplementedwith 9 g of 20% Pd(OH)₂/C and 50% moisture. The medium is purged twicewith nitrogen before introducing 35 bar of hydrogen, and then heated at35° C. for 8 hours. After eliminating the hydrogen, the medium isfiltered. The filtrate is partially concentrated in order to remove thedioxane and the residual aqueous solution is acidified with an aqueoushydrochloric acid solution diluted to a pH equal to 2. The precipitatethus obtained is filtered, drained, washed with distilled water anddried under vacuum. 45 g of compound F are thus obtained in the form ofwhite crystals (yield 97.6%).

Elemental Analysis:

C H N O Calculated 57.90 3.53 24.55 14.02 Found 57.30 3.47 24.35 14.38

NMR (1H, 400 MHz, DMSO d6): 6.38 (s, 1H), 7.56 (m, 1H), 7.62 (dd, 2H),8.43 (dd, 2H), 12.98 (bs, 1H, 13.45 (s, 1H).

NMR (13C, 39.5 MHz, DMSO d6): 80.65, 125.37, 125.59, 128.99, 130.10,137.59, 147.56, 151.05, 163.75

Under an inert gas, 1 g of compound F is solubilized in 400 ml ofanhydrous THF at room temperature. After cooling to 0° C., 333 mg ofLiAlH₄ are added in small fractions over 1 hour. The reaction mediumbecomes opaque and white. The temperature is allowed to rise to roomtemperature. The reaction is monitored by TLC.

After 3 h 30 min, 0.2 eq LiAlH₄ (33 mg) is again added at roomtemperature and then 1 hour later again 0.4 eq of LiAlH₄ (66 mg) andfinally after 45 min, another 0.4 eq (66 mg) of LiAlH₄ is added and themedium is kept stirred at room temperature. After one night, thereaction is complete.

The reaction medium is acidified to a pH equal to 3 with 1 M HCl and itgradually decolorizes. The medium is then extracted with ethyl acetate.A grayish precipitate appears, and it is filtered on No. 4 sinteredglass. The extraction is continued by adding a saturated aqueous NaClsolution. The organic phase is dried over a sodium sulfate, filtered andconcentrated to dryness. An orange-colored solid is thus obtained. Thelatter is washed with Et₂O and then AcOEt and filtered on No. 4 sinteredglass. A pink-beige powder is thus obtained after drying under vacuum.360 mg of compound G are thus isolated with a yield of 38.4%.

Elemental Analysis:

C H N O Calculated 61.67 4.71 26.15 7.47 Found 60.31 4.69 25.90 8.45

Example 2 Synthesis of6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole (H) According toScheme 4 Step 1

Step 1 of example 1 is reproduced in order to obtain compound F.

Under an inert atmosphere, 30 g of compound F are dissolved at roomtemperature in 6 liters of anhydrous methanol. 3 g of 10-camphorsulfonic acid are added and then the medium is heated under reflux for48 hours. The medium is allowed to return to room temperature, andcompound G precipitates on cooling. The compound G thus formed isfiltered, drained and washed several times with ethyl ether before beingdried under vacuum. 23.88 g of methyl ester G are thus obtained in theform of a powder with a yield of 75%

Under an inert atmosphere, 2.33 liters of anhydrous THF and then 20grams of ester G are introduced. After stirring for 15 min, the mediumis cooled to 0° C. and 10.6 g of LiAlH₄ are added in small portions over30 min while the temperature is kept at 0° C. The medium is then heatedunder reflux for 4 h 30 min and then left overnight at room temperature.The medium is then again cooled to 0° C. and hydrolyzed. The precipitateobtained is filtered and drained. The filtrate is concentrated undervacuum to a volume of 200 ml before being acidified to a pH equal to 3with an aqueous solution of dilute hydrochloric acid. The precipitate ofcompound H thus formed is filtered, drained and dried under vacuum,giving 15.5 g of compound H in the form of a beige powder with a yieldof 87.6%.

Examples of Dyeing Examples 3 to 5

The following dyeing compositions were prepared (content in moles):

Examples 3 (Inv) 4 (Inv) 5 (Inv) 6-Hydroxymethyl-3-phenylpyrazolo- 3 ×10⁻³ 3 × 10⁻³ 3 × 10⁻³ [3,2-c]-1,2,4-triazole Para-phenylenediamine 3 ×10⁻³ — — 3,7-Diaminopyrazolo[1,5-a] — 3 × 10⁻³ pyrimidine.2HClN,N-bis-(β-hydroxyethyl)-para- — — 3 × 10⁻³ phenylenediamine.H₂SO₄.H₂ODye carrier (1) (*) (*) (*) Demineralized water qs 100 g 100 g 100 g Dyecarrier (1) Ethyl alcohol at 96° 18 g Sodium metabisulfite as a 35%aqueous solution 0.68 g Pentasodium salt ofdiethylenetriaminopentaacetic acid 1.1 g Aqueous ammonia at 20% 10 g

At the time of use, each composition of examples 3 to 5 is mixed with anequal weight of hydrogen peroxide at 20 volumes (6% by weight).

Each mixture obtained is applied to locks of gray hair which is 90%white, permanently waved (BP) or natural (BN). After leaving in for 30min, the locks are rinsed, washed with standard shampoo, rinsed againand then dried.

The following dyeing results were obtained.

BN BP Example 3 Slightly ash deep purple slightly ash deep purpleExample 4 slightly coppery iridescent red iridescent red Example 5violet intense violet

Examples 6 and 7

The following dyeing compositions were prepared (contents in moles):

Examples 6 (inv) 7 (comp) 6-Hydroxymethyl-3-phenylpyrazolo- 6.4 × 10⁻³[3,2-c]-1,2,4-triazole N,N-bis-(β-hydroxyethyl)-para- 6.4 × 10⁻³ 6.4 ×10⁻³ phenylenediamine.H₂SO₄.H₂O 4,6-Dimethyl-2H-pyrazolo[3,2c]-1, 6.4 ×10⁻³ 2,4-triazole Dye carrier (2) (*) (*) Demineralized water qs 100 g100 g Dye carrier (2) Polyglycerolated oleyl alcohol containing 2 moles4.0 g of glycerol Polyglycerolated oleyl alcohol containing 4 moles 5.69g AS of glycerol containing 78% of active substances (AS) Oleic acid 3.0g Oleyl amine containing 2 moles of ethylene oxide 7.0 g sold under thetrade name ETHOMEEN O12 by the company AKZO Diethylaminopropyllaurylaminosuccinamate, sodium 3.0 g AS salt containing 55% of AS Oleylalcohol 5.0 g Diethanolamide of oleic acid 12.0 g Propylene glycol 3.5 gEthyl alcohol 7.0 g Dipropylene glycol 0.5 g Propylene glycol monomethylether 9.0 g Sodium metabisulfite containing in aqueous solution 0.455 gAS containing 35% of AS Ammonium acetate 0.8 g Antioxidant, sequestrantqs Perfume, preservative qs Aqueous ammonia containing 20% of NH₃ 10.0 g

At the time of use, each composition of Examples 6 and 7 is mixed withan equal weight of hydrogen peroxide at 20 volumes (6% by weight).

Each mixture obtained is applied to locks of gray hair which is 90%white, permanently waved (BP) or natural (BN). After leaving in for 30min, the locks are rinsed, washed with a standard shampoo, rinsed againand then dried.

The color of the locks is evaluated by means of a CM 2002 MINOLTAspectrophotometer. The shades measured on the MINOLTA CM 2002 arecalculated as MUNSELL values (ASTM D 1535-68 standard), in which thevalue H denotes the shade or HUE, the value V denotes the intensity orVALUE, and the value C the purity or CHROMATICITY.

The results are presented in the table below.

Natural gray hair Permanently waved gray hair Examples H V C H V CExample 6 3.1 P 3 4.2 3 P 2.2 4.8 Example 7 0.4 R 4.1 2 6.4 R P 3.4 2.7

These results show that the coupler6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole makes it possibleto obtain more chromatic violet glints.

Examples 8 and 9 Deferred Application

The following compositions were prepared (moles)

Examples 8 9 6-Hydroxymethyl-3-phenylpyrazolo- 3 × 10⁻³ —[3,2-c]-1,2,4-triazole 4,6-Dimethyl-2H-pyrazolo[3,2c]-1, — 3 × 10⁻³2,4-triazole (comp) N,N-bis-(β-hydroxyethyl)-para- 3 × 10⁻³ 3 × 10⁻³phenylenediamine.H₂SO₄.H₂O Dye carrier (3) (*) (*) Demineralized waterqs 100 g 100 g Dye carrier (3) Ethyl alcohol at 96° 18 g Sodiummetabisulfite as a 35% aqueous solution 0.68 g Pentasodium salt ofdiethylenetriaminopentaacetic acid 1.1 g Aqueous ammonia at 20% 10 g

The compositions of examples 8 to 9 are mixed with an equal weight ofhydrogen peroxide at 20 volumes (6% by weight). A portion of each of thecompositions is applied to locks of gray hair which is 90% natural grayhair (BN) or permanently waved gray hair (BP) at the time of the mixing(T0), a second portion is applied to new locks 15 min after the mixing(T15) and a third portion is applied 30 minutes after the mixing (T30).The application to the locks is carried out according to the proceduredescribed above.

The following results were obtained.

COUPLING POWER 90% BN glints 90% BP glints Example 9 T0 4 intense violetintense slightly iridescent iridescent violet T15 3.5 violet iridescentintense slightly iridescent violet T30 3 slightly violet slightlyslightly ash iridescent violet iridescent Example 8 T0 4 very slightlyIntense bluish iridescent bluish violet violet T15 4 ash very slightlyvery slightly ash iridescent bluish bluish violet violet T30 4iridescent very very slightly ash slightly ash bluish violet bluishviolet

The coupling power corresponds to the classification of natural shades(see “Science des Traitements Capillaires” by C. ZVIAK, Ed. Masson 1988,p. 278). A power of 3 corresponds to a dark chestnut 5 brown, a power of4 corresponds to a chestnut brown.

These results show that the coupler6-hydroxymethyl-3-phenylpyrazolo[3,2-c]-1,2,4-triazole exhibits, indeferred application, a lesser variation of the coloration.

1. A composition for dyeing keratinous fibers comprising, in a mediumappropriate for dyeing, at least one compound chosen from apyrazolo[3,2-c]-1,2,4-triazole of formula (I) and the acid additionsalts and base addition salts thereof:

wherein R1 is hydroxymethyl, and R2 is an aryl group optionallysubstituted with at least one radical chosen from halogen, nitro, cyano,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino,sulfonamido, alkylthio, alkoxycarbonyl, carboxy, and sulfo radicals; andat least one oxidation base.
 2. The composition according to claim 1wherein the keratinous fibers are human keratinous fibers.
 3. Thecomposition according to claim 2, wherein the human keratinous fibersare hair.
 4. The composition according to claim 1, wherein R2 is aphenyl group optionally substituted with 1 to 3 radicals.
 5. Thecomposition according to claim 1, wherein the at least one coupler ispresent in the composition in an amount ranging from 0.001% to 10% byweight relative to the total weight of the composition.
 6. Thecomposition according to claim 5, wherein the at least one coupler ispresent in the composition in an amount ranging from 0.005% to 6% byweight relative to the total weight of the composition.
 7. Thecomposition according to claim 1, wherein the at least one oxidationbase is chosen from para-phenylenediamines, bis-phenylalkylenediamines,para-aminophenols, ortho-aminophenols, heterocyclic bases, and the acidaddition salts thereof.
 8. The composition according to claim 1, whereinthe at least one oxidation base is present in the composition in anamount ranging from 0.001% to 10% by weight relative to the total weightof the composition.
 9. The composition according to claim 8, wherein theat least one oxidation base is present in the composition in an amountranging from 0.005% to 6% by weight relative to the total weight of thecomposition.
 10. The composition according to claim 1, furthercomprising a direct dye.
 11. A method for the oxidation dyeing ofkeratinous fibers, comprising applying at least one dyeing compositioncomprising a compound chosen from a pyrazolo[3,2-c]-1 ,2,4-triazole offormula (I) and the acid addition salts and base addition salts thereof:

wherein R1 is hydroxymethyl, and R2 is an aryl group optionallysubstituted with at least one radical chosen from halogen, nitro, cyano,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino,sulfonamido, alkylthio, alkoxycarbonyl, carboxy, and sulfo radicalsisapplied to the keratinous fibers; and developing color with at least oneoxidizing agent.
 12. The method according to claim 11, wherein thekeratinous fibers are human keratinous fibers.
 13. The method accordingto claim 12, wherein the human keratinous fibers are hair.
 14. Themethod according to claim 11, wherein the oxidizing agent is chosen fromhydrogen peroxide, urea peroxide, alkali metal bromates, persalts,peracids, and oxidase enzymes.
 15. The method according to claim 14,wherein the persalts are chosen from perborates and persulfates.
 16. Amethod for the oxidation dyeing of keratinous fibers according to claim11, wherein at least one at least one oxidizing agent is mixed at thetime of application with the dyeing composition.
 17. A method for theoxidation dyeing of keratinous fibers according to claim 11, wherein theat least one oxidizing agent is applied in the form of an oxidizingcomposition simultaneously with or sequentially to the dyeingcomposition.
 18. A multicompartment dyeing kit, comprising a firstcompartment comprising a compound chosen from apyrazolo[3,2-c]-1,2,4-triazole of formula (I) and the acid additionsalts and base addition salts thereof:

wherein R1 is hydroxymethyl, and R2 is an aryl group optionallysubstituted with at least one radical chosen from halogen, nitro, cyano,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino,sulfonamido, alkylthio, alkoxycarbonyl, carboxy, and sulfo radicals; anda second compartment comprising an oxidizing composition.
 19. A coloredproduct obtained by reacting at least one compound chosen from apyrazolo[3,2-c]-1 ,2,4-triazole of formula (I) and the acid additionsalts and base addition salts thereof:

wherein R1 is hydroxymethyl, and R2 is an aryl group optionallysubstituted with at least one radical chosen from halogen, nitro, cyano,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino,sulfonamido, alkylthio, alkoxycarbonyl, carboxy, and sulfo radicals; andat least one oxidation base.
 20. The composition according to claim 1,wherein the pyrazolo[3,2-c]-1,2,4-triazole of formula (I) is chosenfrom: 6-hydroxymethyl-3-phenylpryazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(p-toluyl)pyrazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(o-toluyl)pryazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(m-toluyl)pryazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(3-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(4-hydroxyphenyl)pyrazolo[3,2-c]-1,2,4-triazole,6-hydroxymethyl-3-(3-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole,6hydroxymethyl-3-(4-aminophenyl)pyrazolo[3,2-c]-1,2,4-triazole, and theacid addition salts and base addition salts thereof.
 21. A compositionfor dyeing keratinous fibers comprising, in a medium appropriate fordyeing, a first composition comprising at least one compound chosen froma pyrazolo[3,2-c]-1,2,4-triazole of formula (I) and the acid additionsalts and base addition salts thereof:

wherein R1 is hydroxymethyl, and R2 is an aryl group optionallysubstituted with at least one radical chosen from halogen, nitro, cyano,alkyl, hydroxyl, alkoxy, amino, alkylamino, dialkylamino, acylamino,sulfonamido, alkylthio, alkoxycarbonyl, carboxy, and sulfo radicals; andat least one oxidation base; and a second composition comprising atleast one oxidation agent; wherein, when the first and secondcompositions are mixed and applied to keratinous fibers, decreasedvariance in the coloration of the keratinous fibers results whether thecomposition is applied at the time the first and second compositions aremixed or whether the composition is applied at a deferred timesubsequent to mixing.